Koh Samui is an AMAZING island, with the exception of Chaweng. Picture pretty much any run-down tourist destination on Earth (Daytona Beach (FL), Kuta Beach (Bali), etc.) and that's what you'll find here. Dirty streets, tattoo parlors everywhere, drunk spring-break vibe. Koh Samui is definitely an amazing place to go... but stay away from Chaweng. Much better places are Bo Phut or Lamai.